Amgen and Sanofi Settle Decade-Long Patent Dispute Over PCSK9 Cholesterol Drugs
核心洞察
Amgen and Sanofi have agreed to end their 10-year patent battle over competing PCSK9 inhibitor cholesterol drugs Repatha and Praluent, with both sides withdrawing patent challenges at the European Patent Office.
The settlement comes after years of litigation across multiple jurisdictions including the US, Europe, and Japan, with recent momentum favoring Amgen following favorable rulings at the UPC Court of Appeal and EPO.
Both companies have begun withdrawing their patent attacks, including Sanofi's withdrawal of appeals against Amgen's EP 3 666 797 and Amgen's withdrawal of appeals against Regeneron's EP 3 536 712 B1.
Pharmaceutical giants Amgen and Sanofi have reached a settlement to end their decade-long patent dispute over competing cholesterol-lowering drugs, bringing closure to what industry observers describe as one of the most intense and protracted patent battles in recent pharmaceutical history.
The dispute centered on two PCSK9 inhibitor drugs: Amgen's Repatha (evolocumab) and Sanofi's Praluent (alirocumab), both developed to treat high cholesterol. While Sanofi markets Praluent, the underlying patents are owned by Regeneron Pharmaceuticals, which partnered with Sanofi in the litigation.
Global Legal Battle Spanning Multiple Jurisdictions
The patent war began in 2014 when Amgen sued Sanofi and Regeneron in the United States for patent infringement, arguing that Praluent violated its Repatha patents. The conflict quickly escalated across multiple jurisdictions, including national patent courts in Europe, Japan, and eventually the newly established Unified Patent Court (UPC).
Both companies launched their competing PCSK9 antibodies in 2015, marking the first drugs of this class to receive regulatory approval. The commercial rivalry intensified the patent dispute, with both sides pursuing aggressive litigation strategies across multiple countries.
The legal battle saw significant momentum shifts over the years. Initially, Amgen achieved notable success, including a 2017 US District Court ruling that granted a permanent injunction prohibiting Sanofi and Regeneron from selling Praluent in the United States. However, the tide turned in 2018 when the same Delaware court invalidated central claims of Amgen's Repatha patents, a decision later affirmed by the US Court of Appeals for the Federal Circuit and ultimately confirmed by the US Supreme Court in 2023.
European Patent Office Developments
In Europe, the dispute took on additional complexity. Amgen initially succeeded in obtaining injunctions in several European countries, including a significant 2019 victory at the Regional Court Düsseldorf that temporarily forced Praluent off the German market. Amgen executed this injunction against a security deposit of almost €20 million.
However, the European Patent Office (EPO) Boards of Appeal delivered a surprise ruling in November 2020, restricting Amgen's EP 2 215 124 patent, which had formed the basis for injunctions across European countries. This decision allowed the Higher Regional Court Düsseldorf to permit Sanofi to resume selling Praluent in Germany just one week later.
The restriction of this key patent led to substantial damages claims from Sanofi and Regeneron against Amgen for the period during which they were subject to the injunction. Many of these damages cases remained active until the recent settlement.
UPC Era and Recent Momentum Shift
The launch of the Unified Patent Court in June 2023 added new dimensions to the dispute. On the UPC's first day of operation, both Amgen and Sanofi raced to file competing actions at the court's Munich divisions, with Amgen filing an infringement action and Sanofi filing a revocation action concerning Amgen's patent EP 3 666 797.
The UPC proceedings initially favored Sanofi when the Munich central division overturned Amgen's important EP 797 patent in July 2024, removing the basis for a parallel infringement action against Praluent. However, Amgen's fortunes began to improve in 2025.
A crucial turning point came in April 2025 when the EPO Opposition Division, after four days of oral hearings, found Amgen's EP 797 patent valid as granted. This was followed by an even more significant victory in November 2025, when the UPC Court of Appeal ruled that Amgen's EP 797 was valid, reopening the infringement case at the Munich local division with a hearing scheduled for November 2026.
Settlement Details and Industry Impact
The settlement agreement, reached at the end of last week according to multiple sources, encompasses all proceedings relating to Praluent and Repatha. Both sides have begun the process of mutual withdrawal of their patent challenges at the EPO. Sanofi and Regeneron withdrew their appeals in the opposition case over Amgen's EP 3 666 797, while Amgen withdrew its appeal against Regeneron's EP 3 536 712 B1.
While no appeals have yet been withdrawn at the UPC, sources indicate that lawyers from both sides are currently filing corresponding applications. The specific terms of the settlement remain confidential, with neither Amgen nor Sanofi making public announcements regarding the agreement.
The settlement comes as a surprise given the intensity with which both sides fought for over ten years and the recent momentum shift in Amgen's favor. The resolution eliminates the uncertainty that had surrounded both companies' cholesterol drug franchises and removes the substantial legal costs associated with maintaining litigation across multiple jurisdictions.
Legal Teams and Representation
The protracted dispute involved numerous law firms and patent attorneys across different jurisdictions. In Europe, Amgen primarily relied on teams from Brinkhof and Bardehle Pagenberg, with Brinkhof partner Koen Bijvank playing a central role in recent EPO proceedings and Bardehle Pagenberg partner Johannes Heselberger leading UPC cases alongside Bijvank.
Sanofi and Regeneron retained their established advisors Carpmaels & Ransford and Hoffmann Eitle, with Daniel Wise leading the Carpmaels team. Former Hoffmann Eitle partner Niels Hölder, who led infringement cases for Regeneron before moving to Carpmaels & Ransford in early 2026, was also instrumental in the litigation strategy.
The resolution of this landmark patent dispute removes a significant overhang for both companies and provides clarity for the competitive landscape in the PCSK9 inhibitor market, allowing both firms to focus on commercial competition rather than courtroom battles.